Haunted is a primary antagonist and an officer within the organization Valhalla, serving as a formidable and unsettling adversary to the characters of the story. His background is shrouded in mystery, with his personal history remaining completely unknown, although he is known to be a former Catholic priest. He is an exceptionally dangerous individual, classified as an S-rank magic user, and his actions are driven not by ideology but by a deeply personal and warped aesthetic. Over the course of his life, he has been responsible for the deaths of nearly thirteen thousand people, viewing each as a personal experience to savor.

Haunted's personality is defined by his profound and singular obsession with human despair. He lives for the purpose of witnessing what he considers the most beautiful moment of a person's life: their final moments before death, when their emotions are at their peak. His love for humanity is expressed through this twisted lens, as he seeks to draw out and indulge in the suffering and anguish of others. He is not motivated by mass destruction for its own sake, as he finds the impersonal nature of mass murder wasteful and in bad taste; instead, he prefers to kill slowly and intimately to fully appreciate each victim's emotional state. This macabre philosophy makes him an agent of pure chaos who acts solely in his own self-interest. His demeanor is mercurial, shifting from friendly and gentlemanly to crude, scheming, and openly perverse, and he rarely hides his true thoughts or emotions, a trait that makes him deeply unpleasant to be around. He is also a member of Valhalla, an organization dedicated to recovering witches, though his role within it serves primarily to facilitate his own pursuits.

Haunted’s motivations are straightforward in their horror: to cause as much despair as possible in others. This drive forms the core of his every action. He is fixated on the witch Mari Nikaido, though his feelings manifest as a dangerous obsession rather than genuine affection. He tricked Mari into working for him by taking the orphans she grew up with as hostages, promising to keep them safe in exchange for her cooperation, only to later reveal that he had killed the children long ago. His goal with Mari is not to kill her quickly but to continuously exhaust and revel in her emotions for his own delight, to the point where even his fellow Valhalla officers note that harming her would incur his eternal wrath. Similarly, he becomes intensely interested in the protagonist, Takeru Kusanagi, whom he identifies as a “beacon of hope.” Haunted finds Takeru’s pure intent and desire to save everything without sacrifice to be the perfect antithesis to his own being, and he is disgusted by it, dedicating significant effort to snuffing out that hope.

In the story, Haunted serves as a major antagonistic force, particularly for the 35th Test Platoon. He is first introduced during a mock battle at the Anti-Magic Academy, where he murders several students and soldiers before trapping the platoon within a magical barrier. During this encounter, he reveals his connection to Mari and battles Takeru, proving himself the more skilled swordsman. It is during this fight that he is defeated, not by direct force, but by Takeru’s tactics and Mari’s powerful magic. Despite this defeat, he escapes through a portal, remaining a persistent and looming threat. Haunted is also known for his long-standing enmity with Hayato Kurogane, the captain of the Inquisition’s elite EXE unit. Haunted despises Kurogane for his emotionless demeanor, which deprives Haunted of the pleasure he seeks from his victims, and he fears Kurogane’s ability to permanently kill him.

His key relationships are defined by his obsession with despair. Beyond Mari and Takeru, he has a notable relationship with his own weapon, the legendary magical blade Dainsleif, which he refers to as Nacht. As a fellow purveyor of chaos, Nacht chose Haunted as her master, and their relationship is one of two twisted equals who bicker but see each other as eternal companions. He has a tense relationship with other Valhalla leaders, such as Orochi and Mother Goose, with whom he fought in the past. While they do not agree with his methods, dealing with him is considered more effort than it is worth. He also despises Sougetsu Ootori, the Chairman of the Inquisition, as he learns of Sougetsu’s plan to bring about the apocalypse, which would leave Haunted with no one left to torment.

Throughout the narrative, Haunted’s role is to embody pure, unrelenting evil. He is an agent of despair who pushes the other characters to their limits. His development is not one of redemption or change but of escalation; his schemes grow increasingly personal and cruel. His greatest act of malice is turning Takeru’s own sister into a mindless killing machine, forcing Takeru into an impossible choice. In his final moments, even after being defeated, he attempts to kill Takeru one last time, not for any strategic gain, but simply to destroy the hope the protagonist represents.

Haunted is a formidable combatant with a range of notable abilities. He is a highly skilled swordsman, capable of outmatching Takeru in direct combat. His primary magical power is the manipulation of Despair Magic, a rare ancient attribute that allows him to cause immense suffering. He is also proficient in necromancy, able to control the dead, perform summoning rituals, and practice alchemy. He wields the legendary weapon Dainsleif (named Nacht), a powerful magical sword that is his constant companion. Most significantly, Haunted has the ability to stockpile extra lives, having accumulated thousands of them over his long life. This makes him extraordinarily difficult to kill permanently, as seen when Hayato Kurogane burned through two thousand of these lives in a single five-minute engagement.